The stars participated in a funny Late Night with Seth Meyers segment

JOHN STAMOS: LETTING LORI LOUGHLIN GET AWAY

PHOTO: BROADIMAGE/REX/SHUTTERSTOCK

Hindsight is always 20/20, isn’t it?

In a new segment for Late Night with Seth Meyers called “A Message to My Younger Self,” stars Keri Russell, John Stamos, Henry Cavill and John Goodman all took some time to shell out advice they would give to their former selves.

The impressively ageless Stamos won the segment with a jokey gem about how he preserved his looks.

“Hey, little John. You will have a fantastic life as long as you make sure you do one thing,” said the Fuller House star, 52. “Now, on your 18th birthday, the Prince of Darkness – Satan – will offer you eternal youth in exchange for your soul. Little John, I’m telling you right now: You take that deal, son.”

Russell, 40, also poked fun at herself – specifically that haircut during season 2 of Felicity.

“Hey little Keri. It’s me, older Keri,” The Americans star said. “Your life is going to be so exciting, but whatever you do, don’t cut your hair short during the second season of Felicity. No, I’m serious. People will freak the hell out. You’ll get hate mail. You’ll even get death threats. But, gradually, your hair will grow back and your fans will forgive you, but you will never – and I repeat never – forgive your fans.”

Cavill, meanwhile, kidded about his role as Superman in the upcoming Batman v Superman: Dawn of Justice.

“Hey, little Henry. Your life is going to be filled with so much joy and happiness, but when you turn my age, your biggest dream will come true. You finally get to be in a Batman movie. You know how you have all those Batman posters in your bedroom and how you run around pretending to Batman and always say: ‘Batman rules! He could beat any other superhero in a fight, hands down. It shouldn’t even be a question!’ ” Cavill, 32, said. “Well, Henry, this movie has it all. The Batsuit, the car and all the cool gadgets – as for your part in the film … I think it’s best we wait until you’re old enough to handle it.”

As for Goodman? He referenced one very specific incident from his past – watch the clip to find out exactly what still haunts him to this day.

Late Night with Seth Meyers airs weeknights (12:35 a.m. ET) on NBC